Japanese gardeners are much admired for the scrupulous care they take of their plants, particularly in the winter months. One example is yukitsuri (雪吊りliterally, ‘snow sling’), a triangular arrangement of ropes on a frame that is attached to pine trees in the winter months to protect their branches from being damaged by the weight of heavy snow.
Farmers in northern Honshu began the practice to protect their apple trees from being weighed down by fruit and late-autumn snowfall. From there, the habit of rigging up yukitsuri spread throughout Japan. Tokyo doesn’t receive much snow these days, but yukitsuri are still a common sight, even if only for decorative purposes and as fūbutsushi (風物詩 seasonal marker).
Setting up yukitsuri at Kenrokuen garden in Kanazawa, Ishikawa Prefecture. | Oilstreet, CC BY-SA 3.0, via Wikimedia Commons
Another common sight in Japanese gardens in the winter months is shimo-yoke (霜除け), straw wrapping for plants from warmer climes that insulate them against frost, thereby helping them survive the winter.
These ingenious innovations have helped countless plants survive winters that would otherwise have killed them and are a tribute to the care and attention Japanese gardeners lavish on their plants.
But there is one innovation whose days would appear to be numbered. Komomaki (菰巻き, also known as waramaki 藁巻き) are straw belts that are wrapped around the trunks of pine trees at the onset of winter in Japan to protect them against pests.
The custom dates back to the Edo period when a gardener came up with the idea of using straw belts as a way of dealing with the matsukareha (マツカレハ or 松枯葉蛾), or pine moths (Dendrolimus spectabilis), which feed on pine needles. Left unchecked, their voracious appetites can weaken pine trees.
The idea is that when the temperature drops, the pine moths come down from the trees in search of the warmer temperatures to be found in the soil at the foot of the tree. The straw mat mimics the insulation of the ground. By keeping the upper tie of the komomaki loose and the lower tie tight, the moths get in but cannot get out. and stay in the mats through the winter months.
Come early February, while the moths are still hibernating, the mats are removed and burned, killing them and leaving the tree unharmed. Their ashes are used as fertiliser for the tree.
However, the wisdom of this time-honoured custom has been called into question in recent years. In 2005, a study of the komomaki at Himeji castle by Chikako Niiho and others from the Himeji Institute of Technology discovered that only six of the 1,577 insects caught in komomaki that year (0.3%) were pine moths. The rest of them were insects that are actually beneficial for pine trees.
Faced with incontrovertible proof of the pitifully low number of pine moths caught in komomaki, Japan’s gardeners, generally the epitome of prudent conservatism, have had to accept that their forefathers might have been barking up the wrong tree all along.
While komomaki are still used in nine traditional gardens in Tokyo to mark the passing of autumn, the Imperial Palace no longer uses them at all. Whether other gardens will follow suit remains to be seen.
Japanese gardeners are much admired for the scrupulous care they take of their plants, particularly in the winter months. One example is yukitsuri (雪吊りliterally, ‘snow sling’), a triangular arrangement of ropes on a frame that is attached to pine trees in the winter months to protect their branches from being damaged by the weight of heavy snow.
Farmers in northern Honshu began the practice to protect their apple trees from being weighed down by fruit and late-autumn snowfall. From there, the habit of rigging up yukitsuri spread throughout Japan. Tokyo doesn’t receive much snow these days, but yukitsuri are still a common sight, even if only for decorative purposes and as fūbutsushi (風物詩 seasonal marker).
Setting up yukitsuri at Kenrokuen garden in Kanazawa, Ishikawa Prefecture. | Oilstreet, CC BY-SA 3.0, via Wikimedia Commons
Another common sight in Japanese gardens in the winter months is shimo-yoke (霜除け), straw wrapping for plants from warmer climes that insulate them against frost, thereby helping them survive the winter.
These ingenious innovations have helped countless plants survive winters that would otherwise have killed them and are a tribute to the care and attention Japanese gardeners lavish on their plants.
But there is one innovation whose days would appear to be numbered. Komomaki (菰巻き, also known as waramaki 藁巻き) are straw belts that are wrapped around the trunks of pine trees at the onset of winter in Japan to protect them against pests.
The custom dates back to the Edo period when a gardener came up with the idea of using straw belts as a way of dealing with the matsukareha (マツカレハ or 松枯葉蛾), or pine moths (Dendrolimus spectabilis), which feed on pine needles. Left unchecked, their voracious appetites can weaken pine trees.
The idea is that when the temperature drops, the pine moths come down from the trees in search of the warmer temperatures to be found in the soil at the foot of the tree. The straw mat mimics the insulation of the ground. By keeping the upper tie of the komomaki loose and the lower tie tight, the moths get in but cannot get out. and stay in the mats through the winter months.
Come early February, while the moths are still hibernating, the mats are removed and burned, killing them and leaving the tree unharmed. Their ashes are used as fertiliser for the tree.
Komomaki in Hama-rikyu, Tokyo. | Paul Asman and Jill Lenoble, CC 2.0 / © Flickr.com
However, the wisdom of this time-honoured custom has been called into question in recent years. In 2005, a study of the komomaki at Himeji castle by Chikako Niiho and others from the Himeji Institute of Technology discovered that only six of the 1,577 insects caught in komomaki that year (0.3%) were pine moths. The rest of them were insects that are actually beneficial for pine trees.
Faced with incontrovertible proof of the pitifully low number of pine moths caught in komomaki, Japan’s gardeners, generally the epitome of prudent conservatism, have had to accept that their forefathers might have been barking up the wrong tree all along.
While komomaki are still used in nine traditional gardens in Tokyo to mark the passing of autumn, the Imperial Palace no longer uses them at all. Whether other gardens will follow suit remains to be seen.